hw/9pfs/virtio-9p-xattr-user.c

   1 /*
   2  * Virtio 9p user. xattr callback
   3  *
   4  * Copyright IBM, Corp. 2010
   5  *
   6  * Authors:
   7  * Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include <sys/types.h>
  15 #include "hw/virtio.h"
  16 #include "virtio-9p.h"
  17 #include "fsdev/file-op-9p.h"
  18 #include "virtio-9p-xattr.h"
  19
  20
  21 static ssize_t mp_user_getxattr(FsContext *ctx, const char *path,
  22                                 const char *name, void *value, size_t size)
  23 {
  24     char buffer[PATH_MAX];
  25     if (strncmp(name, "user.virtfs.", 12) == 0) {
  26         /*
  27          * Don't allow fetch of user.virtfs namesapce
  28          * in case of mapped security
  29          */
  30         errno = ENOATTR;
  31         return -1;
  32     }
  33     return lgetxattr(rpath(ctx, path, buffer), name, value, size);
  34 }
  35
  36 static ssize_t mp_user_listxattr(FsContext *ctx, const char *path,
  37                                  char *name, void *value, size_t size)
  38 {
  39     int name_size = strlen(name) + 1;
  40     if (strncmp(name, "user.virtfs.", 12) == 0) {
  41
  42         /*  check if it is a mapped posix acl */
  43         if (strncmp(name, "user.virtfs.system.posix_acl_", 29) == 0) {
  44             /* adjust the name and size */
  45             name += 12;
  46             name_size -= 12;
  47         } else {
  48             /*
  49              * Don't allow fetch of user.virtfs namesapce
  50              * in case of mapped security
  51              */
  52             return 0;
  53         }
  54     }
  55     if (!value) {
  56         return name_size;
  57     }
  58
  59     if (size < name_size) {
  60         errno = ERANGE;
  61         return -1;
  62     }
  63
  64     /* name_size includes the trailing NUL. */
  65     memcpy(value, name, name_size);
  66     return name_size;
  67 }
  68
  69 static int mp_user_setxattr(FsContext *ctx, const char *path, const char *name,
  70                             void *value, size_t size, int flags)
  71 {
  72     char buffer[PATH_MAX];
  73     if (strncmp(name, "user.virtfs.", 12) == 0) {
  74         /*
  75          * Don't allow fetch of user.virtfs namesapce
  76          * in case of mapped security
  77          */
  78         errno = EACCES;
  79         return -1;
  80     }
  81     return lsetxattr(rpath(ctx, path, buffer), name, value, size, flags);
  82 }
  83
  84 static int mp_user_removexattr(FsContext *ctx,
  85                                const char *path, const char *name)
  86 {
  87     char buffer[PATH_MAX];
  88     if (strncmp(name, "user.virtfs.", 12) == 0) {
  89         /*
  90          * Don't allow fetch of user.virtfs namesapce
  91          * in case of mapped security
  92          */
  93         errno = EACCES;
  94         return -1;
  95     }
  96     return lremovexattr(rpath(ctx, path, buffer), name);
  97 }
  98
  99 XattrOperations mapped_user_xattr = {
 100     .name = "user.",
 101     .getxattr = mp_user_getxattr,
 102     .setxattr = mp_user_setxattr,
 103     .listxattr = mp_user_listxattr,
 104     .removexattr = mp_user_removexattr,
 105 };
 106
 107 XattrOperations passthrough_user_xattr = {
 108     .name = "user.",
 109     .getxattr = pt_getxattr,
 110     .setxattr = pt_setxattr,
 111     .listxattr = pt_listxattr,
 112     .removexattr = pt_removexattr,
 113 };